Chemotherapy Alone Versus Chemotherapy Plus Targeted Therapy as Adjuvant Therapy for Initially Unresectable Colorectal Cancer Liver Metastases: A Retrospective Cohort Study

This multi-center study enrolled consecutive patients with initially unresectable CRLM who underwent conversion therapy or radiofrequency ablation (RFA) and achieved no NED status between June 1, 2013, and June 30, 2020, from Zhongshan Hospital of Shanghai, Zhongshan Hospital of Xiamen, Cancer Hospital of Beijing. The inclusion criteria were as follows: (1) with histologically confirmed CRC; (2) with initially unresectable synchronous liver metastases (LMs); (3) accepted conversion therapy and successfully converted into resectable status; (4) underwent R0 intestinal and hepatic resection; (5) accepted adjuvant therapy. The exclusion criteria were as follows: (1) R1/R2 resection; (2) extrahepatic metastases; (3) accepted postoperative monotherapy; (4) lack of follow-up data. According to the adjuvant therapy regimen (with or without targeted therapy), the cohorts were divided into CA cohort and CT cohort. The study was approved by the ethics committee of three medical centers and was adhered to Good Clinical Practice guidelines and the Declaration of Helsinki. Written informed consent was obtained from all participants.